1. Field of the Invention
The present invention relates to a vibratory sieve for sifting fibrous materials like asbestos from massed materials containing them.
2. Description of the Prior Art
Asbestos has been frequently used as refractory materials such as building materials. Since it has been recently found that asbestos is carcinogenic, repair works are under way to remove asbestos from the walls of public facilities and the like. If the asbestos-containing waste thus removed is discarded as it is, the asbestos dust suspends in air at the dumping site and flies away, tending to scatter a source of pollutant. Consequently asbestos must be separated from such waste before disposal. At present, attention is directed to the use of a vibratory sieve to separate the asbestos at low costs. In the operation of the vibratory sieve, the asbestos-containing waste is comminuted and mixed with water, the mixture is placed onto the vibrating screen of a sieve, and finer particles and water are passed through screen meshes, leaving the separated asbestos on the screen.
Asbestos and like fibrous materials are easily entangled in screen meshes, thereby directly causing clogging in screen meshes. Because of this drawback, vibratory sieves have entailed difficulties in separating fibrous materials like asbestos.